Helmets without ear pads are really designed for specific situations, not everyday resort skiing. They're most common in ski racing (where athletes wear separate chin guards and prioritize minimal bulk) or multi-sport helmets that get used for biking or skating in the off-season.
The downside for regular skiing is significant: no ear coverage means no protection from cold wind and no impact padding on the sides of your head. Your ears will freeze on cold days, and you lose a layer of protection in side-impact falls.
For most skiers and snowboarders, a helmet with removable insulated ear pads is a much better choice. You get warmth and protection when you need it, and you can pop the pads off for sunny spring days. Skip the no-ear-pad option unless you're specifically racing or using the helmet across multiple sports.